Low-GWP blowing agents are going to be introduced to the market in the next few years and it will be necessary to optimise spray foam systems to use these ingredients.
By Christian Eilbracht, Carsten Schiller, Robert Tauchen and Wiley Rowe of Evonik.
Spray foam formulations are unusual among polyurethane systems; they must have a long shelf life and they are complex mixtures of ingredients. Surfactants can have a significant impact the shelf life, chemical compatibility and physical properties, of these formulations.
We have found that surfactants play an important role in terms of spray-foam physical properties, flow, appearance and formulation shelf-life.
Additionally, this work shows that our Tergostab B84715 material gives good all-round properties in a standard formulation but that other surfactants may be more suitable if a high R-value or improved FR are required in different formulations.
To reach this conclusion we tested ten Evonik surfactants.
In July 2015, the EPA announced final regulations changing the status of several products with high Global Warming Potential (GWP) used in polyurethane foam. As a result, users have been instructed to stop using hydrofluorocarbons (HFCs) in some applications and switch to low GWP alternatives like 4th generation blowing agents, hydrofluoroolefins (HFOs). The GWP of the new HFOs is typically 1% of HFCs.
The spray foam industry has to face this change and it will be…